Joining stretchable fabric portions to one another

ABSTRACT

A method of joining first and second stretchable fabric portions to one another in a desired configuration comprises the steps of sewing a first thread through at least one of the first and second fabric portions to define a first stitch formation looping a second thread within the first stitch formation such that the second thread and the first thread overlap one another to create a sewn seam, one of the threads being a fusible thread and the other of the threads being a non-fusible thread; positioning the first and second fabric portions relative to one another in a desired configuration; melting the fusible thread; and forming a plurality of discrete bonding element portions extending along a bonding path. The discrete bonding element portions retain the first and second fabric portions in the desired configuration.

This application is a divisional of U.S. patent application Ser. No.12/323,971, filed Nov. 26, 2008, now U.S. Pat. No. 8,440,036, which ishereby incorporated by reference in its entirety.

This invention relates to a method of joining first and secondstretchable fabric portions to one another in a desired configuration, afabric construction comprising first and second fabric portions joinedto one another in a desired configuration, and a garment comprising sucha fabric construction.

In garment manufacture it is often necessary to join two fabric portionsto one another, in a desired configuration to create a garment. Any suchjoin between fabric portions must be sufficiently strong to maintain thefabric portions in the desired configuration during, for example wearingor washing of the garment.

It is known to join two fabric portions to one another in a desiredconfiguration using a stitch formation in which one or more sewingthreads is sewn through both fabric portions to join the fabric portionstogether.

However, imbuing such conventional stitch formations with sufficientstrength to withstand wear and washing results in a bulky join or seam.The inclusion of a bulky seam in a garment is undesirable, particular inintimate apparel such as underwear or tights which are worn next to awearer's skin, since the bulky seam can make the garment uncomfortable.

As an alternative to conventional stitch formations, a fusible threadmay be used to bond one fabric portion to another.

The structure of a fusible thread, for example one formed from athermoplastic yarn such as copolyamide, or a thermosetting yarn,undergoes a molecular change when heated and melts to form a bondingagent. Subsequent cooling causes the bonding agent to set. Accordinglyit is possible to use the fusible thread like an adhesive to bond twofabric portions together. The join between the two portions formed inthis manner is less bulky than a seam formed by conventional stitchformations.

However, when set the bonding agent is brittle, and so any deformationof the respective fabric portions causes the bonding agent to shatter.This reduces the extent of bonding between the fabric portions, and soallows the two portions to separate.

Therefore, there is a need for an improved manner of joining twostretchable fabric portions to one another in a desired configurationthat produces an unobtrusive join of sufficient strength which is ableto accommodate stretching of the fabric portions.

According to a first aspect of the invention there is provided a methodof joining first and second stretchable fabric portions to one anotherin a desired configuration comprising the steps of:

-   -   sewing a first thread through at least one of the first and        second fabric portions to define a first stitch formation;    -   looping a second thread within the first stitch formation such        that the second thread and the first thread overlap one another        to create a sewn seam, one of said threads being a fusible        thread and the other of said threads being a non-fusible thread;    -   positioning the first and second fabric portions relative to one        another in a desired configuration; and    -   melting the fusible thread; and    -   forming a plurality of discrete bonding element portions        extending along a bonding path, the discrete bonding element        portions retaining the first and second fabric portions in the        desired configuration.

The provision of a plurality of discrete bonding element portions allowsthe bonding element portions to move relative to one another. Thispermits the bonding element portions to accommodate stretching of thefabric portions without shattering, thereby maintaining the extent ofbonding between the fabric portions, and so preventing the fabricportions from separating.

In addition the inclusion of a fusible second thread within the firststitch formation introduces a chemical bonding element to the joinbetween the two fabric portions, and so permits the use of a firstthread having a low yarn count, and hence a low bulk, while maintainingthe strength of the join between the fabric portions. In turn, a lowbulk first thread reduces the bulk of the first stitch formation, and noprovides an unobtrusive join between the fabric portions.

In a preferred embodiment of the invention, sewing a first threadincludes sewing a non-fusible first thread through the first fabricportion to define the first stitch formation; and

-   -   positioning the first and second fabric portions relative to one        another includes positioning the first and second fabric        portions relative to one another so as to adopt a first        overlying configuration with a fusible second thread lying        between the first and second fabric portions.

In another preferred embodiment of the invention, sewing a first threadincludes sewing a non-fusible first thread through the first and secondfabric portions to define a first stitch formation; and

-   -   positioning the first and second fabric portions relative to one        another includes positioning the first and second fabric        portions relative to one another so as to adopt a second        overlying configuration with a fusible second thread lying        between respective regions of one of the first or second fabric        portions.

In a further preferred embodiment of the invention, sewing a firstthread includes sewing a first thread through the first and secondfabric portions to define a first stitch formation; and

-   -   positioning the first and second fabric portions relative to one        another includes positioning the first and second fabric        portions relative to one another so as to adopt an open        configuration with the first and second fabric portions        extending in opposite directions away from the first stitch        formation.

The foregoing steps permit the relative positioning of the first andsecond fabric portions in each of the first and second overlyingconfiguration and the open configuration, respectively, as desired.

Preferably looping a sewing looper thread within the first stitchformation includes feeding the fusible looper thread and the sewinglooper thread through the same looper member. Such a step convenientlylays the foregoing looper threads into the first stitch formation is thedesired parallel arrangement.

Preferably the method further includes the step of looping a thirdthread between the first thread and the second thread. The looping of athird thread in this way provides additional support to the first stitchformation, thereby increasing the robustness thereof. In addition, thethird thread may absorb the melted fusible second thread where itoverlaps the second thread. This increases the number of discretebonding element portions in a controlled and regular manner, and soallows them to accommodate further stretching of the fabric portionswhile maintaining the extent of bonding between the fabric portions.

The method may include arranging the threads in an overlook stitchconfiguration having a needle thread, one or more lower looper threads,and an upper looper thread.

Arranging the threads in this manner allows for the finishing of an edgeof at least one of the first and second fabric portions while providingthe desired joining of the fabric portions to one another.

Optionally the method includes arranging the threads in an ISO 504overlook stitch configuration with the first sewing thread defining theneedle thread, the second thread is defining a lower looper thread, andthe third thread defining the upper looper thread.

Another embodiment of the method includes arranging the threads in anISO 505 overlock stitch configuration with the first sewing threaddefining the needle thread, the second thread defining a lower looperthread, and the third thread defining the upper looper thread.

Such steps provide one or more of the fabric portions with desirablefinished edge characteristics while joining the fabric portions to oneanother.

Optionally the fusible thread is lad within the sewn seam together witha non-fusible fourth thread such that the fourth thread and the fusiblethread lie parallel to one another.

The looping of a fourth thread together with the fusible thread providesadditional support to the discrete bonding elements portions, therebyincreasing the robustness of the join between the fabric portions,without impacting on the discrete nature of these elements.

Conveniently the fusible thread is a composite thread comprising a corenon-fusible thread about which is wound a fusible yarn. Such a compositethread increases the robustness of the join between the fabric portionswithout the need to introduce a non-fusible fourth thread.

In a preferred embodiment of the invention after forming the pluralityof discrete bonding element portions, one or more non-fusible threadsare removed. Such a step reduces further the bulk of any join betweenthe fabric portions. In addition it allows for the removal of a visiblemeans, i.e. the non-fusible thread, of joining fabric portions from,e.g. a garment formed from the fabric portions.

According to a second aspect of the invention there is provided a fabricconstruction comprising:

-   -   first and second stretchable fabric portions joined to one        another in a desired configuration; and    -   a plurality of discrete bonding element portions formed from a        fusible thread, the discrete bonding element portions extending        along a bonding path and retaining the first and second fabric        portions in the desired configuration.

According to a third aspect of the invention there is provided a garmentcomprising a fabric construction as described hereinabove.

The second and third aspects of the invention share the advantages ofthe first aspect of the invention.

There now follows a brief description of preferred embodiments of theinvention, by way of non-limiting examples, with reference to theaccompanying drawings in which:

FIG. 1( a) schematically shows, from below, a stitch structure formed bya method according to a first embodiment of the invention;

FIG. 1( b) is a side view of the stitch structure shown in FIG. 1( a);

FIG. 1( c) shows the stitch structure shown in FIG. 1( a) followingmelting of a fusible second thread therein;

FIG. 1( d) shows the stitch structure of FIG. 3 after removal of thefirst thread therein;

FIG. 2( a) shows a stitch structure formed by a method according to asecond embodiment of the invention;

FIG. 2( b) shows first and second fabric portions in a first overlyingconfiguration,

FIG. 3( a) shows a schematic view of discrete bonding element portionswhile respective fabric portions are in a relaxed state;

FIG. 3( b) shows a schematic view of discrete bonding element portionswhile respective fabric portions are in a stretched state;

FIG. 4 shows an enlarged view of a stitch structure formed by a methodaccording to a third embodiment of the invention.

FIGS. 5( a) and 5(b) show a stitch structure formed by a methodaccording to a fourth embodiment of the invention;

FIG. 5( c) shows first and second fabric portions in a second overlyingconfiguration;

FIGS. 6( a) and 6(b) show a stitch structure formed by a methodaccording to a fifth embodiment of the invention;

FIG. 6( c) shows first and second fabric portions in an openconfiguration;

FIG. 7( a) shows a further schematic view of discrete bonding elementportions while respective fabric portions are in a relaxed state; and

FIG. 7( b) shows a schematic view of the discrete bonding elementportions shown in FIG. 7( a) while respective fabric portions are in astretched state.

A schematic view of a stitch structure formed by a first embodiment ofthe method of the to invention is designated generally by the referencenumeral 10, as shown in FIG. 1( a).

The first stitch structure 10 is a simple two thread sewn seam formed bysewing a non-fusible first thread 12 through a first stretchable fabricportion 32 (FIG. 1( b)) to define a first stitch formation 14, and bylooping a fusible second thread 16 within the first stitch formation 14such that the fusible second thread 16 and the first thread 12 overlapone another. This is indicated more clearly in FIG. 1( b) wherein itwill be noted that the second thread 16 extends across a surface 32 a ofthe first fabric portion 32 in face contact therewith and at discretelocations 13 along the second thread 16 the first thread 12 is formedinto bridge-like formations 12 a each of which overlies the secondthread 16 in a bridge like manner.

In accordance with the present invention, a second fabric portion 36 isto be secured to the first fabric portion 32. This is achieved asillustrated in FIG. 1( b) by positioning the second fabric portion 36over the first fabric portion 32 with the second thread 16 locatedtherebetween. The fabric portions 32, 36 are then held together whilethe fusible second thread 15 is melted, using heat for example, and aplurality of discrete bonding element portions 20, as shown in FIG. 1(c) are formed. The discrete bonding element portions 20 extend along abonding path 18 and bond the fabric portions 32, 36 together, andthereby retain the fabric portions 32, 36 in the desired configuration.

The bridge-like formations 12 a are located between the second thread 16and the second fabric portion 36 at locations 13 and so during meltingof the fusible second thread 16 act to shield the fusible second thread16 from the second fabric portion 36 in order to prevent or weakenbonding of the first and second fabric portions 32, 36 at theselocations and also, as seen more clearly in FIG. 1( c), create thediscrete bonding element portions 20 from the melted second thread 16(each bonding element portion 20 extending between adjacent locations13).

Accordingly the formation of the discrete bonding element portions 20 isachieved by the bridge-like formations 12 a of the non-fusible firstthread 12 causing the melted second thread 16 to flow away from and/orbe absorbed into the non-fusible thread 12 and thereby create points ofweakness in the melted second thread 16. Optionally the melted secondthread 16 may be further made to flow away from the non-fusible firstthread 12 by additionally applying pressure to the fabric portions 32,36.

The creation of the aforementioned points of weakness allows the meltedfusible second thread 16 to break in preference at these points ofweakness (rather than shatter) to create the plurality of discretebonding element portions 20. Subsequent stretching and/or mechanicaldeformation of the fabric portions 32, 36 can be used to form theplurality of discrete bonding element portions 20.

In other embodiments the action of melting the fusible second thread 16may be sufficient to sever the melted fusible second thread 16completely to form directly the plurality of discrete bonding elementportions 20.

These discrete bonding element portions 20 retain the first and secondstretchable fabric portions 32, 36 in a desired relative configuration.

In accordance with the present invention, the discrete bonding elementportions 20 are able to move relative to one another; in this respectadjacent element portions 20 are able to pivot relative to one anotherat locations 13 and/or are able to move apart from one another at theselocations. This movement between adjacent bonding element portions 20accommodates stretching of the joined together fabric portions 32, 36.

The fusible thread may be formed completely from a heat settableplastics material such as a polyamide, for example, Grilon K-110 havinga yarn count of about 235 dtex.

This can be advantageous since it enables, if desirable, the non-fusiblefirst thread 12 to be removed since, after melting, the second thread 16no longer exists at locations 13. This provides a bonded connectionbetween the fabric portions 32, 36 which is relatively invisible (i.e.there is no visible thread giving the appearance of a sewn seam) andwhich is less bulky than a conventional sewn seam.

As seen in FIGS. 1( a) and 1(c) the relative orientation between bondingelement portions 20 is determined by the ‘bridging’ first thread 12;this orientation can be modified to accommodate desirable stretchingcharacteristics of the joined fabric portions 32, 36. Examples of somodifying the orientation of bonding element portions 20 are given inthe following embodiments.

FIG. 2( a) shows a second stitch structure 30 formed by a secondembodiment of the method of the invention.

The second stitch structure 30 is formed by sewing a non-fusible firstthread 12 through a first fabric portion 32 to define a first stitchformation 14, and by looping a fusible second thread 16 within the firststitch formation 14 such that the fusible second thread 16 and the firstthread 12 overlap one another.

In addition, a non-fusible third thread 34 is looped between the firstthread 12 and the fusible second thread 16.

The first and third threads 12, 34 and the fusible second thread 16 arearranged in an overlook stitch configuration, and more particularly inan International Standards Organisation (ISO) 504 stitch configuration.In this configuration the first thread 12 defines the needle thread, thefusible second thread 16 defines a lower looper thread, and the thirdthread 34 defines the upper looper thread.

Other embodiments of the method of the invention my produce a stitchstructure having a differing stitch configuration.

Following formation of the aforementioned stitch configuration, thefirst fabric portion 32 is positioned relative to a second stretchablefabric portion 36 in a first overlying configuration, as shown in FIG.2( b), with the fusible second thread 16 lying between the first andsecond fabric portions 32, 36.

The fusible second thread 16 is now melted using, for example, a heatpress to form a plurality of discrete bonding element portions (notshown).

In particular, the first and third threads 12, 34 act on the fusiblesecond thread 16 where they overlap to create a plurality of discretebonding element portions 20 extending along a bonding path 18, as shownschematically in FIGS. 3( a) and 3(b).

The discrete bonding element portions 20 join the first and secondfabric portions 32, 36 to one another, and so retain them in thedesired, first overlying configuration.

The first and third threads 12, 34 may act on the second thread 16 byabsorbing the melted second thread 16, or by severing the melted secondthread 16 where they overlap. Alternatively the first and third threads12, 34 may deform the second thread 16 where they overlap to createpoints of weakness that break in preference to shattering of the meltedsecond thread 16.

FIG. 3( a) shows the relative arrangement of the discrete bondingelement portions 20 while the first fabric portion 32 and the secondfabric portion (not shown) are in a relaxed, i.e. un-stretched, state.

The discrete bonding element portions 20 are able to move relative toone another, and so are able to accommodate stretching of the first 32and second fabric portions by moving away from one another, as shown inFIG. 3( b).

FIG. 4 shows an enlarged view of a third stitch structure 40 formed by athird embodiment of the method of the invention.

The third stitch structure 40 is identical to the second stitchstructure 30, except that while looping a fusible second thread 16within the first stitch formation 14 a fourth thread 42 is also loopedwithin the first stitch formation 14 so as to lie parallel with thefusible second thread 16. The fourth thread 42 provides additionalsupport to the discrete bonding element portions (not shown) followingmelting of the fusible second thread 16.

A convenient way of looping the fourth thread 42 with the fusible secondthread 16 is to feed the second and fourth threads 16, 42 through thesame looper member (not shown).

Preferably the type of yarn chosen for the fourth thread 42 is resistantto the melted second thread 16, and no minimises any absorption of thediscrete bonding element portions 20 formed from the second thread 16.

The third stitch structure 40 functions in the same manner as describedhereinabove in relation to the second stitch structure 30.

FIGS. 5( a) and 5(b) show a fourth stitch structure 50 formed by afourth embodiment of the method of the invention

The fourth stitch structure 50 is formed by sewing a first thread 12through first and second fabric portions 32, 36 to define a first stitchformation 14, looping a fusible second thread 16 within the first stitchformation 14 such that the fusible second thread 16 and the first thread12 overlap one another, and looping a third thread 34 between the firstthread 12 and the fusible second thread 16.

The first and third threads 12, 34 and the fusible second thread 16 arearranged in the International Standards Organisation (ISO) 504 stitchconfiguration, with the first thread 12 defining the needle thread, thefusible second thread 16 defining the lower looper thread, and the thirdthread 34 defining the upper looper thread.

Following formation of the aforementioned stitch configuration, thefirst fabric portion 32 is positioned relative to a second stretchablefabric portion 36 in a second overlying configuration, as shown in FIG.5( c), with the fusible second thread 16 lying between respectiveregions of the second fabric portion 36.

In other embodiments of the invention the fusible second thread 16 maylie between respective regions of the first fabric portion 32.

The fusible second thread 16 is now melted to form a plurality ofdiscrete bonding element portions (not shown).

The plurality of discrete bonding element portions 20, as shownschematically in FIGS. 3( a) and 3(b), may be formed by any of themechanisms described hereinabove.

The discrete bonding element portions 20 join the respective regions ofthe second fabric portion 36 to one another, and so retain the first andsecond fabric portions 32, 36 in the desired, second overlyingconfiguration.

The fourth stitch structure 50 may also include a sewing fourth thread(not shown) which is looped within the first stitch formation so as tolie parallel with the fusible second thread 16.

FIGS. 6( a) and 6(b) show a fifth stitch structure 60 formed by a fifthembodiment of the method of the invention

The fifth stitch structure 60 is formed by sewing a first thread 12through first and second fabric portions 32, 36 to define a first stitchformation 14, looping a fusible second thread 16 within the first stitchformation 14 such that the fusible second thread 16 and the first thread12 overlap one another, and looping a third thread 34 between the firstthread 12 and the fusible second thread 16.

The first and third threads 12, 34 and the fusible second thread 16 arearranged in the International Standards Organisation (ISO) 505 stitchconfiguration. The first thread 12 defines the needle thread, thefusible second thread 16 defines the lower looper thread, and the thirdthread 34 defines the upper looper thread.

In other embodiments of the invention the threads 12, 16, 34 may bearranged in a different configuration.

The fifth stitch structure 60 may also include a fourth thread (notshown) which is looped within the first stitch formation so as to lieparallel with the fusible second thread 16.

Following formation of the aforementioned stitch configuration, thefirst fabric portion 32 is positioned relative to a second stretchablefabric portion 36 in an open configuration, as shown schematically inFIG. 6( c), with the first and second fabric portions 32, 36 extendingin opposite directions away from the first stitch formation 14.

The fusible second thread 16 is now melted and a plurality of discretebonding element portions formed (not shown)

In the embodiment shown the first and third threads 12, 34 absorb thefusible second thread 16 where they overlap the fusible second thread16, thereby forming a plurality of discrete bonding element portions 20extending along a bonding path 18, as shown schematically in FIGS. 7( a)and 7(b).

The discrete bonding element portions 20 prevent pulling out of thefirst and third sewing threads 14, 34 from the first stitch structure14, and so retain the first and second fabric portions 32, 36 in thedesired, open configuration.

FIG. 7( a) shows the relative arrangement of the discrete bondingelement portions 20 formed by the fifth method of the invention. In thisfigure the arrangement of the discrete bonding element portions 20 isshown while the first fabric portion 32 and the second fabric portion(not shown) are in a relaxed, i.e. un-stretched state.

The discrete bonding element portions 20 are able to move relative toone another, and so are able to accommodate stretching of the first 32and second fabric portions by moving away from one another, as shown inFIG. 7( b).

In the above examples, the fusible thread 16 is preferably formed from aheat settable plastics material such as a polyamide. A suitable threadis a Grilon® K-110 having a yarn count of about 235 dtex. Alternatively,the fusible thread 16 may be a composite yarn having a fusible yarnwrapped about a non-fusible core thread. A suitable composite yarn isfor example Hemsafe 4002 as supplied by Wykes.

In the above examples, the non-fusible thread is preferably amultifilament polyester having a yarn count in the range of 80-150 dtex.A suitable yarn is Skala 240 or 360 as supplied by Gutermann.

The invention claimed is:
 1. A fabric construction comprising: first andsecond stretchable fabric portions joined to one another in a desiredoverlying configuration; and a plurality of discrete bonding elementportions formed from a fusible thread and lying between respectivefabric portions, the discrete bonding element portions being separatedand spaced from one another by a non-fusible thread arranged in a firststitch formation, the discrete bonding element portions extending alonga bonding path, and the discrete bonding element portions adhering thefirst and second fabric portions in the desired overlying configuration.2. A garment comprising a fabric construction, and wherein the fabricconstruction comprises: first and second stretchable fabric portionsjoined to one another in a desired overlying configuration; and aplurality of discrete bonding element portions formed from a fusiblethread and lying between respective fabric portions, the discretebonding element portions being separated and spaced from one another bya non-fusible thread arranged in a first stitch formation, the discretebonding element portions extending along a bonding path, and thediscrete bonding element portions adhering the first and second fabricportions in the desired overlying configuration.